Local host is the ip for machine hosting the forum.
You need to create a database in mysql through a admin program, and put that name of the databse into your php code, as well as your users name and password. Many php and mysql setups come with passwords and user names, you need to have a look in the read me files for these.
it looks like some of the lower statements you state your self, such as the table, you need to name it. Not sure what user table is, i feel its the same as other tables.
How good is your html skills? If you continue to have problems i have a php code that allows you to display the contents of a databse and add a new record. All you need to do is change the html tags from a standard 3 field by 3 column table that displays the data.